Checks for input file existence first.

src/main.py

@@ -7,6 +7,7 @@
 import argparse as ap
 import sys
 import json
+from os.path import exists
 
 # Libraries for image processing
 import numpy as np
@@ -59,7 +60,11 @@ class apply_filters:
         self.output_file = self.args.output_file
         self.dpi = self.args.dpi
         self.mirror = True if self.args.mirror else False
-        self.run()
+        if exists(self.input_file):
+            self.run()
+        else:
+            print("Input file does not exist", file=sys.stderr)
+            exit(1)
 
     def run(self):
         # read as numpy.array